MODERN DATABASE MGMT.(PEARSON CHANNEL)
13th Edition
ISBN: 9780136709299
Author: Hoffer
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 2, Problem 2.34PAE
The Is Married To relationship in Figure 2-12a would seem to have an obvious answer in Problem and Exercise is, until time plays a role in modeling data. Draw a data model for the PERSON entity type and the Is Married TO relationship for each of the following variations by showing the appropriate cardinalities and including, if necessary, any attributes:
- All we need to know is who a person is currently married to, if anyone. (This is likely what you represented in your answer to problem and Exercise 2-33d.)
- We need to know who a person has ever been married to, if anyone.
- We need to know who a person has ever been married to, if anyone, as well as the date of their marriage and the date, if any, of the dissolution of their marriage.
- The same situation as in c, but now assume (which you likely did not do in c) that the same two people can remarry each other after a dissolution of a prior marriage to each other.
- In history, and even in some cultures today, there may be no legal restriction on the number of people to whom one can be currently married. Does your answer to part c of this Problem and Exercise handle this situation or must you make some changes (if so, draw a new ERD).
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
Create an Entity-Relationship Model to represent the data requirements of the problem given below. Specify the cardinalities of relationships and all-important constraints. Also mention the assumptions if you have made any.
A person can be an employee, alumnus or a student. For person P_id (identifier), date of birth, gender and contacts are stored. Person can have more than one contact numbers and there are no other types of person that exists. An instance of person can belong to more than one type. Date hired and salary is the unique attributes of employee. For alumnus degree is required to be stored that comprises of year and designation. Major department is the attribute of student. A student can be a graduate student or an undergraduate student but not both at the same time. No other type of student exists. For graduate student test score is stored and for undergraduate student class standing is stored. Employee can be faculty, staff or others but not both at the same time. For…
Create an Entity-Relationship Model to represent the data requirements of the problem given below. Specify the cardinalities of relationships and all-important constraints. Also mention the assumptions if you have made any.
A person can be an employee,alumnus or a student.For person P_id(identifier), date of birth,gender and contacts are stored. Person can have more than one contact numbers and there are no other types of person that exists.An instance of person can belong to more than one type.Date hired and salary is the unique attributes of employee.For alumnus degree is required to be stored that comprises of year and designation. Major department is the attribute of student. A student can be a graduate student or an undergraduate student but not both at the same time.No other type of student exists.For graduate student test score is stored and for undergraduate student class standing is stored.Employee can be faculty, staff or others but not both at the same time. For faculty…
The model above needs some improvement. Where you can apply all the normalization rules to attributes. Furthermore, you also need to explain entities and relations between them, and the purpose of attributes by showing why and how they exist ?.
Chapter 2 Solutions
MODERN DATABASE MGMT.(PEARSON CHANNEL)
Ch. 2 - Define each of the following terms: entity type...Ch. 2 - Match the following terms and definitions....Ch. 2 - Contrast the following terms: stored attribute;...Ch. 2 - Prob. 2.4RQCh. 2 - Prob. 2.5RQCh. 2 - Prob. 2.6RQCh. 2 - State six general guidelines for naming data...Ch. 2 - Prob. 2.8RQCh. 2 - Prob. 2.9RQCh. 2 - State three conditions that suggest the designer...
Ch. 2 - List the four types of cardinality constraints,...Ch. 2 - Give an example, Other than those described in...Ch. 2 - What is the degree of a relationship? List the...Ch. 2 - Give an example (Other than those described in...Ch. 2 - Give an example of each of the following, other...Ch. 2 - Give an example of the use of effective (or...Ch. 2 - State a rule that says when to extract an...Ch. 2 - Prob. 2.18RQCh. 2 - In addition to explaining what action is being...Ch. 2 - For the Manages relationship in Figure 2-12a,...Ch. 2 - Explain the distinction between entity type and...Ch. 2 - Why is it recommended that every ternary...Ch. 2 - A cellular operator needs a database to keep track...Ch. 2 - Prob. 2.24PAECh. 2 - Answer the following questions concerning Figure...Ch. 2 - Prob. 2.26PAECh. 2 - You may have been assigned a CASE or a drawing...Ch. 2 - Consider the two E-R diagrams in Figure 2-25 Q,...Ch. 2 - Prob. 2.29PAECh. 2 - Are associative entities also weak entities? Why...Ch. 2 - Because Visio does not explicitly show associative...Ch. 2 - Figure 2-26 shows a grade report that is mailed to...Ch. 2 - Prob. 2.33PAECh. 2 - The Is Married To relationship in Figure 2-12a...Ch. 2 - Figure 2-27 represents a situation of students who...Ch. 2 - Figure 2-28 shows two diagrams (A and B), both of...Ch. 2 - Prob. 2.37PAECh. 2 - Review Figure 2-8LQ and Figure 2-22. Identify any...Ch. 2 - Prob. 2.39PAECh. 2 - Prob. 2.40PAECh. 2 - Prob. 2.41PAECh. 2 - Prob. 2.42PAECh. 2 - Prob. 2.43PAECh. 2 - Prob. 2.44PAECh. 2 - Prob. 2.45PAECh. 2 - Prob. 2.46PAECh. 2 - Prob. 2.47PAECh. 2 - Prob. 2.48PAECh. 2 - Draw an ERD for the following situation. (State...Ch. 2 - Prob. 2.50PAECh. 2 - Prob. 2.51PAECh. 2 - Review your answer to Problem and Exercise 2-49 if...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, computer-science and related others by exploring similar questions and additional content below.Similar questions
- It is possible to can convert any weak entity set to a strong entity set by simply addingappropriate attributes. Why, then, do we have weak entity sets?arrow_forwardCreate an Entity-Relationship Model to represent the data requirements of the problem given below. Specify the cardinalities of relationships and all-important constraints. Also mention the assumptions if you have made any. [20 Marks] A person can be an employee, alumnus or a student. For person P_id (identifier), date of birth, gender and contacts are stored. Person can have more than one contact numbers and there are no other types of person that exists. An instance of person can belong to more than one type. Date hired and salary is the unique attributes of employee. For alumnus degree is required to be stored that comprises of year and designation. Major department is the attribute of student. A student can be a graduate student or an undergraduate student but not both at the same time. No other type of student exists. For graduate student test score is stored and for undergraduate student class standing is stored. Employee can be faculty, staff or others but not both at the same…arrow_forwardUse ER Assistant to draw your diagram. Draw a self-referencing entity type for the Employee entity type for which an employee is supervised by a maximum of one other employee and doesn’t have to be supervised by any employee at all. Conversely, an employee can supervise zero or many other employees. The attributes of the Employee entity are as follows: EmpNo (primary key), EmpName, EmpAddress.arrow_forward
- ER model relationships are represented using a.) relationship keys b.) primary keys c.) crows foot symbols d.) main keys What do the cardinalities in an ER model show, (please select all that apply)? a.) only a one to one relationship. b.) the minimum number of entities that can be involved in a relationship. c.) only a many to many relationship.arrow_forwardSuppose that we wish to keep a genealogy. The information we wish to record about each person includes their name, date of birth, phone number, and degrees obtained . We also need to keep track of the mother, father, and children of each person. Draw a complete Entity-Relationship diagram. You must include all the details, sad as keys, weak entities (if any), cardinality constraints, etc. Your diagram must avoid redundancy.arrow_forwardCreate an Entity-Relationship Model to represent the data requirements of the problem given below. Specify the cardinalities of relationships and all-important constraints. Also mention the assumptions if you have made any. A person can be an employee, alumnus or a student. For person P id (identifier), date of birth, gender and contacts are stored. Person can have more than one contact numbers and there are no other types of person that exists. An instance of person can belong to more than one type. Date hired and salary is the unique attributes of employee. For alumnus degree is required to be stored that comprises of year and designation. Major department is the attribute of student. A student can be a graduate student or an undergraduate student but not both at the same time. No other type of student exists. For graduate student test score is stored and for undergraduate student class standing is stored. Employee can be faculty, staff or others but not both at the same time. For…arrow_forward
- Draw an Entity Relationship diagram for modeling the following system. Use relational modelling techniques in your design. You are free to make reasonable assumptions for your model unless they conflict with the definition below. Also explain your design with a paragraph. [Caution: Create your solution using paper and pen. Then put the image of your solution here. Drawing/writing with computer tools will not be accepted. Also include your name and signature in the solution paper]Problem definition: “There is a need to keep track of data for a hospital. The hospital building consists of several departments. Each department is identified with its name. For each department, the following data should also be stored: the number of floors, opening hour, and closing hour. Each department has a number of rooms. Each room is identified by its room number, but there might be rooms with the same name in different departments. At each department, many doctors and nurses can work.A doctor is…arrow_forwardEvery weak entity set can be converted to a strong entity set by simply adding theappropriate attributes. Why, then, do we have weak entity sets?arrow_forwardCreate Entity-Relationship (E-R) model for the internal view of gym membership system including all workers and organization units affected by processing gym memberships. When members join the gym, they pay a fee for a certain length of time. Most memberships are for one year, but memberships as short as two months are available. Throughout the year, the gym offers a variety of discounts on their regular membership prices (e.g., two memberships for the price of one for Valentine's day). It is common for members to pay different amounts for the same length of membership. The gym wants to mail out reminder letters to members asking them to renew their memberships one month before their memberships expire. Some members have become angry when asked to renew at a much higher rate than their original membership contract, so the club wants to track the prices paid so that the manager can override the regular prices with special prices when members are asked to renew. The system must track…arrow_forward
- Note: Please make sure that all the points/rules must be implemented.Draw the ERD Diagram to create relational model corresponding to the described Scenario. The loan office in a bank receives from various parties, requests to investigate the credit status of aCustomers. Each credit request is identified by a Request ID and is described by a Request Date andRequesting party Name. The loan office also received results of credit checks. A credit check is identifiedBy a credit check ID and is described by the credit check Date and the credit rating. The loan officeMatches credit requests with credit check results. A credit request may be recorded before its resultArrives; a particular credit result may be used in support of several credit requests. Draw ERD for thisSituation. Requirements:ER Diagram of system implemented in tool such as Sqlyog & Draw.io (Available online).arrow_forwardER-diagrams are high-level design of the Database. The given ER-diagram describes the Dentist office and service details. are there strong and weak entities, recursive relationships and different attribute types are involved ? would you identify what eachentity are relationship are and to describe all constraintsrelated to themarrow_forwardDraw these on the given diagram: Associations (aggregations/compositions if needed) with names and multiplicities, generalization, attributes (withvisibility and attribute types).arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Database System ConceptsComputer ScienceISBN:9780078022159Author:Abraham Silberschatz Professor, Henry F. Korth, S. SudarshanPublisher:McGraw-Hill EducationStarting Out with Python (4th Edition)Computer ScienceISBN:9780134444321Author:Tony GaddisPublisher:PEARSONDigital Fundamentals (11th Edition)Computer ScienceISBN:9780132737968Author:Thomas L. FloydPublisher:PEARSON
- C How to Program (8th Edition)Computer ScienceISBN:9780133976892Author:Paul J. Deitel, Harvey DeitelPublisher:PEARSONDatabase Systems: Design, Implementation, & Manag...Computer ScienceISBN:9781337627900Author:Carlos Coronel, Steven MorrisPublisher:Cengage LearningProgrammable Logic ControllersComputer ScienceISBN:9780073373843Author:Frank D. PetruzellaPublisher:McGraw-Hill Education
Database System Concepts
Computer Science
ISBN:9780078022159
Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan
Publisher:McGraw-Hill Education
Starting Out with Python (4th Edition)
Computer Science
ISBN:9780134444321
Author:Tony Gaddis
Publisher:PEARSON
Digital Fundamentals (11th Edition)
Computer Science
ISBN:9780132737968
Author:Thomas L. Floyd
Publisher:PEARSON
C How to Program (8th Edition)
Computer Science
ISBN:9780133976892
Author:Paul J. Deitel, Harvey Deitel
Publisher:PEARSON
Database Systems: Design, Implementation, & Manag...
Computer Science
ISBN:9781337627900
Author:Carlos Coronel, Steven Morris
Publisher:Cengage Learning
Programmable Logic Controllers
Computer Science
ISBN:9780073373843
Author:Frank D. Petruzella
Publisher:McGraw-Hill Education
Enhanced Entity Relationship Model; Author: Data Science Center;https://www.youtube.com/watch?v=ocQUtXPumdQ;License: Standard YouTube License, CC-BY